Dr. Khaleel Alyahya
Dr. Jamila El-Medany
OBJECTIVES
At the end of the lecture, students should be able
to:
List the different bones of the UL.
 List the characteristic features of each bone.
Differentiate between the bones of the right and
left sides.
List the articulations between the different bones.
Bones of
Pectoral Girdle.
Arm : Humerus.
Forearm : Radius & Ulna.
Wrist : Carpal bones
Hand: Metacarpals &
Phalanges
Pectoral Girdle
 Formed of Two Bones:
 Clavicle and Scapula.
 It is very light and
allows the upper limb to
have exceptionally free
movement.
Clavicle
 It is a doubly curved long bone lying
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horizontally across the root of the neck
It is subcutaneous throughout its length.
Functions:
1. It serves as a rigid support from which
the scapula and free upper limb are
suspended keeping them away from the
trunk so that the arm has maximum
freedom of movement.
2. Transmits forces from the upper limb
to the axial skeleton.
3. Provides attachment for muscles.
4. It forms a boundary of the
Cervicoaxillary canal for protection of
the neurovascular bundle of the UL.
Clavicle
It is considered as a long bone but it has no
medullary (bone marrow) cavity.
Its Medial (Sternal) end is enlarged & triangular.
Its Lateral (Acromial) end is flattened.
 The medial 2/3 of the Body (Shaft) is convex
forward.
 The lateral 1/3 is concave forward.
 These curves give the clavicle its appearance of
an elongated Capital (S)
 It has (2) Surfaces:
 Superior : smooth as it lies just deep to the
skin.
 Inferior : rough because strong ligaments bind
it to the 1st rib.
Articulations
 It articulates Medially with
the manubrium of the
Sternum at the
Sternoclavicular joint .
 Laterally with the
Scapula at the
Acromioclavicular joint
 Inferiorly with the 1st rib
at the Costoclavicular
Joint
Fractures of the Clavicle
 The clavicle is commonly fractured especially
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in children as forces are impacted to the
outstretched hand during falling.
The weakest part of the clavicle is the
junction of the middle and lateral thirds.
After fracture, the medial fragment is
elevated (by the sternomastoid muscle), the
lateral fragment drops because of the
weight of the UL.
It may be pulled medially by the adductors of
the arm.
The sagging limb is supported by the other.
Scapula (Shoulder Blade)
 It is a triangular Flat bone.
 Extends between the 2nd _ 7th ribs.
 It Has :
 Three Processes:
 (1)Spine: a thick projecting ridge of bone that
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continues laterally as the flat expanded
(2) Acromion : forms the subcutaneous point of the
shoulder.
(3) Coracoid: a beaklike process. It resembles in size,
shape and direction a bent finger pointing to the
shoulder.
Three Borders: Superior, Medial (Vertebral) &
Lateral (Axillary) (the thickest) part of the bone.
It terminates at the lateral angle .
 Three Angles :
 Superior.
 Lateral (forms the Glenoid cavity) : a shallow
concave oval fossa that receives the head of
the humerus. &
 Inferior.
 Two Surfaces:
1. Convex Posterior : divided by the spine of the
scapula into the smaller Supraspinous Fossa
 (above the spine) and the larger
 Infraspinous Fossa (below the spine).
2.Concave Anterior (Costal) : it forms the
large Subscapular Fossa.
Suprascapular Notch: a nerve passageway,
medial to coracoid process.
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Functions
. Gives attachment to muscles.
2.Has a considerable degree of
movement on the thoracic wall
to enable the arm to move freely.
3. The glenoid cavity forms the
socket of the shoulder joint.
Because most of the scapula is
well protected by muscles and
by its association with the
thoracic wall , most of its
fractures involve the protruding
subcutaneous Acromion.
1
Humerus
surgical
 A typical Long bone.
 It is the largest bone in the UL
 Proximal End :
 Head, Neck, Greater & Lesser Tubercles.
 Head: Smooth& forms
 1/3 of a sphere, it articulates with the
glenoid cavity of the scapula.
 Anatomical neck: formed by a groove
separating the head from the tubercles.
 Greater tubercle: at the lateral margin of
the humerus.
 Lesser tubercle: projects anteriorly.
 The two tubercles are separated by
 Intertubercular Groove.
 Surgical Neck: a narrow part distal to the
tubercles.
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Shaft (Body):
Has two prominent features:
1. Deltoid tuberosity:
A rough elevation laterally for the
attachment of deltoid muscle.
2. Spiral (Radial) groove:
Runs obliquely down the posterior
aspect of the shaft.
It lodges the important radial nerve &
vessels.
Distal End:
Widens as the sharp medial and
lateral Supracondylar Ridges form
and end in the Medial and Lateral
Epicondyles providing muscular
attachment.
 Trochlea: (medial) for
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articulation with the ulna
Capitulum: (lateral) for
articulation with the radius.
Coronoid fossa :above the
trochlea (anteriorly)
Radial fossa: above the
capitulum (anteriorly)
Olecranon fossa : above the
trochlea (posteriorly).
Fractures of Humerus
 Most common fractures are of the
Surgical Neck especially in elder
people with osteoporosis.
 The fracture results from falling on
the hand (transition of force
through the bones of forearm of
the extended limb).
 In younger people, fractures of the
greater tubercle results from
falling on the hand when the arm
is abducted .
 The body of the humerus can be
fractured by a direct blow to the
arm or by indirect injury as
falling on the oustretched hand.
Nerves affected in
fractures of humerus
Surgical neck:
Axillary nerve
Radial groove:
Radial nerve.
Distal end of
humerus: Median
nerve.
Medial epicondyle :
Ulnar nerve.
Ulna
 It is the stabilizing bone of the
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forearm.
It is the medial & longer of the two
bones of the forearm.
Proximal End
Olecranon Process : projects
proximally from the posterior
aspect(forms the prominence of the
elbow).
Coronoid Process : projects
anteriorly.
Tuberosity of Ulna: inferior to
coronoid process.
Trochlear Notch: articulates with
trochlea of humerus.
Radial Notch : a smooth rounded
concavity lateral to coronoid process.
Ulna
 Shaft :
 Thick & cylindrical superiorly but
diminishes in diameter inferiorly
 Three surfaces (Anterior, Medial &
Posterior).
 Sharp Lateral Interosseous border.
 Distal End:
Small rounded Head .
Styloid process: Medial.
 The head lies distally at the wrist.
 The articulations between the ulna &
humerus at the elbow joint allows
primarly only flexion & extension
(small amount of abduction &
adduction occurs).
Radius
 It is the shorter and lateral of the two
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forearm bones.
Proximal End:
1. Head: small & circular&
Its upper surface is concave for
articulation with the Capitulum.
2. Neck.
3. Radial (Biciptal) Tuberosity :
medially directed and separates
the proximal end from the body.
Shaft:
Has a lateral convexity.
It gradually enlarges as it passes
distally.
Radius
 Distal (Lower) End:
 It is rectangular.
 Its medial aspect forms a concavity :
Ulnar Notch to accommodate the
head of the ulna.
 Radial Styloid process: extends from
the lateral aspect.
 Dorsal tubercle: projects dorsally.
Fractures of radius & ulna
 Because the radius & ulna are firmly bound by
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the interosseous membrane, a fracture of one
bone is commonly associated with dislocation of
the nearest joint.
Colle’ s Fracture (fracture of the distal end of
radius) is the most common fracture of the
forearm.
It is more common in women after middle age
because of osteoporosis.
It results from forced dorsiflexion of the hand as
a result to ease a fall by outstretching the upper
limb.
The typical history of the fracture includes
slipping. Because of the rich blood supply to the
distal end of the radius, bony union is usually
good.
WRIST ( CARPUS)
 Composed of Eight Carpal bones arranged
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in two irregular rows, of four each.
These Small bones give flexibility to the
wrist.
The carpus presents Concavity on their
Anterior surface & Convex from side to side
Posteriorly.
Proximal row (from lateral to medial):
Scaphoid, Lunate, Triquetral & Pisiform
bones.
Distal row (from lateral to medial):
Trapezium, Trapezoid,
Capitate & Hamate.
Fracture of
Scaphoid
It is the most commonly
fractured carpal bone and it is
the most common injury of the
wrist.
It is the result of a fall onto the
palm when the hand is abducted.
Pain occurs along the lateral side
of the wrist especially during
dorsiflexion and abduction of the
hand.
Union of the bone may take
several months because of poor
blood supply to the proximal
part of the scaphoid.
Metacarpaus
 It is the skeleton of the hand between the
carpus and phalanges.
 It is composed of
Five Metacarpal
bones, each has a Base, Shaft, and a
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Head.
They are numbered 1-5 from the thumb.
The distal ends (Heads) articulate with the
proximal phalanges to form the Knuckles
of the fist.
The Bases of the metacarpals articulate
with the carpal bones. The 1st metacarpal is
the shortest and most mobile.
3rd metacarpal has a styloid process on the
lateral side of the base.
Digits
 Each digit has Three Phalanges
 Except the Thumb which has only
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Two
Each phalanx has a Base
Proximally, a Head distally and a
Body between the base and the
head.
The proximal phalanx is the
largest.
The middle ones are intermediate in
size.
The distal ones are the smallest, its
distal ends are flattened and
expanded distally to form the nail
beds.
THANK YOU